Disclosed herein is a locking structure for skin terminals in a seat back of a vehicle seat, particularly to a vehicle rear seat, and a vehicle rear seat provided with a locking structure.
A seat back of a vehicle seat in the related art, such as an automobile rear seat, is formed by placing a cushion material into a frame and covering it with a skin. It is known that in order to dispose loads or the like on a back surface when the seat back is folded forward onto a seat cushion, a planar carpet is adhered on the back surface side of the frame.
As a structure for locking a terminal of the skin of such a seat back and a terminal of the carpet, there is a proposed structure for locking a skin terminal onto a back surface of a frame by inserting a retainer fixed to the skin terminal into a tucking groove formed on the back surface of the frame and nipping a carpet terminal in the tucking groove by this retainer (for example, refer to U.S. Pat. No. 5,503,454 (“the '454 patent”)).
In the structure described in the '454 patent, as shown in FIG. 5, a retainer 150 having a J-shaped section is sewed and fixed to a terminal 130a of a skin 130 along a back surface 130b of the skin 130. When being inserted into a tucking groove 100b formed on a planar back surface 100a of a frame 100, the retainer 150 is fixed in the tucking groove 100b by a repulsive force of the retainer 150. This tucking groove 100b has a U-shaped section including an inner wall 100c and an outer wall 100d, and is formed along an entire outer edge on the back surface 100a of the frame 100.
A carpet 140 is integrally applied and attached to the back surface 100a of the frame 100. A terminal 140a of the carpet 140 is applied along the inner wall 100c in the tucking groove 100b. The terminal 130a of the skin 130 is fixed in the tucking groove 100b by inserting and fixing the retainer 150 into the tucking groove 100b. The terminal 140a of the carpet 140 is nipped by the retainer 150 and the inner wall 100c and fixed in the tucking groove 100b. 
However, in the locking structure as in the '454 patent, although the skin terminal 130a is fixed to the frame back surface 100a and the carpet terminal 140a is nipped by the frame back surface 100a by inserting the retainer 150 fixed to the skin terminal 130a into the tucking groove 100b of the frame back surface 100a, the retainer 150 is only inserted into the tucking groove 100b. Thus, in a case where a force in the direction in which the retainer 150 is pulled out is applied to the skin 130 from the outside, there is a fear that the retainer is removed from the tucking groove 100b. Therefore, further rigidity improvement in the locking structure for the skin terminals is desired.
In this locking structure, the tucking groove 100b is not provided with a guide portion for inserting the skin terminal 130a and the carpet terminal 140a. Therefore, at the time of inserting the skin terminal 130a and the carpet terminal 140a into the tucking groove 100b, further improvement in workability is desired.
Further, in this locking structure, the retainer 150 fixed to the skin terminal 130a is inserted and fixed into the tucking groove 100b. Thus, further compact arrangement and downsizing are desired.